1. Field of the Invention:
This invention relates to hair-dyeing preparations based on oxidation dyes. The hair-dyeing preparations in question contain oxidation dye precursors in a cosmetic carrier. The oxidation dye precursors used are developer substances and coupler substances which form dyes under the effect of oxidizing agents or atmospheric oxygen. Suitable cosmetic carriers for the oxidation dye precursors include creams, emulsions, gels, shampoos, foam aerosols or other preparations which are suitable for application to the hair.
2. Statement of Related Art:
By virtue of their bright colors and good fastness properties, oxidation dyes, which are formed by the oxidative coupling of one or more developer components with one another or with one or more coupler components, play a prominent part in the dyeing of hair. The developer substances normally used include primary, aromatic amines containing another free or substituted hydroxy or amino moiety in the para or ortho position, diaminopyridine derivatives, heterocyclic hydrazone derivatives, 3-aminopyrazolone derivatives and tetraaminopyrimidines. Useful couplers include m- phenylenediamine derivatives, napthols, resorcinol derivatives and pyrazolones.
Good oxidation dye precursors primarily have to satisfy the requirement of forming the desired shades of color with sufficient intensity during the oxidative coupling reaction. In addition, they must be readily taken up by human hair without excessive staining of the scalp. The hair colors produced must show high stability to heat and light and to the chemicals used in the permanent waving of hair. Finally, the oxidation hair dye precursors must be both toxicologically and dermatologically safe.